/*
 * Copyright 2008 Christopher Davies
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.googlecode.textish.tokenizer;

import java.util.Iterator;
import java.util.List;

/**
 * Tokenizes a list of {@link LineToken}s and {@link EmptyLineToken}s into a
 * list of {@link ParagraphToken}s.
 * 
 * @author cgdavies
 * 
 */
public class ParagraphTokenizer implements ITokenizer {

	public void tokenize(CharSequence context, List input, List output) {
		TokenBuilder paragraphBuilder = ParagraphToken.createBuilder();

		for (Iterator it = input.iterator(); it.hasNext();) {
			IToken token = (IToken) it.next();

			if (token instanceof LineToken)
				paragraphBuilder.append(token);
			else if (token instanceof EmptyLineToken) {
				IToken paragraphToken = paragraphBuilder.build();

				if (paragraphToken != null)
					output.add(paragraphToken);
			}
			else
				throw new UnexpectedTokenException(token.getClass());
		}
		
		IToken paragraphToken = paragraphBuilder.build();
		if (paragraphToken != null)
			output.add(paragraphToken);
	}

}
